The present invention relates to a composition for diffusing to combat bacteria contained in the air in an enclosure to be treated. The invention also relates to a method of combating bacteria comprising a step of diffusing said composition. Finally, the invention relates to the use of a catalytic combustion flask for implementing such a method.
In the present invention, combating bacteria covers both bactericidal activity (which term is used to designate a substance having the property of killing bacteria), and also bacteriostatic activity (which term is used to designate a substance that shows the development of such bacteria). Those two forms of activity are covered by the term xe2x80x9cantibacterialxe2x80x9d.
Presently known techniques for combating bacteria implement disinfectants which are generally applied directly to contaminated surfaces.
Of the wide range of compounds known for conserving an antibacterial preservative, mention can be made of 2-phenylphenol, known commercially as xe2x80x9cpreventol O extraxe2x80x9d or indeed xe2x80x9cE 231xe2x80x9d. This compound is used in the preparation of numerous disinfectants and detergents and can also be used for preserving a large number of products. 2-phenylphenol possesses a vast spectrum of effectiveness against bacteria, yeasts, molds, etc.
Extra red thyme essence, in its commercial form, is another compound known for having antibacterial activity. It is used in certain pharmaceuticals such as toothpastes, antiseptics for mouthwashes, . . . . Extra red thyme essence contains 40% up to a maximum of 52% by weight of natural thymol, about 20% of para-cymene, about 3% to 4% of carvacrol, with the remainder being constituted by terpenes and alcohols.
Synthetic thymol is also known.
These two compounds are thus well known as antibacterials and they act by contact on surfaces to be treated.
Devices also exist for purifying air. They are in the form of ionizers, purifiers, sprays, or aerosol cans.
Ionizers are more specifically adapted to combating dust. The drawback is that using them contributes to emitting ozone and that can be dangerous for man.
Air purifiers act more specifically on dust in the air.
Sprays and aerosols cans serve to diffuse the substances they contain in air in the form of more or less fine droplets, which substances act likewise mainly by contact, given the dimensions of the droplets.
These large-sized droplets provide a specific surface area for action that is smaller than that which could be obtained with a greater quantity of droplets that are smaller.
Nevertheless, there is nothing to prevent antibacterial compositions being diffused by means of sprays or aerosol cans. However, any antibacterial effects of such devices against bacteria contained in the air within an enclosure has yet to be observed or demonstrated. Furthermore, that mode of diffusion remains very local and can only be curative. Also, concentrations of active substances remain quite high and thus relatively harmful and/or unpleasant for the user.
The present invention seeks to mitigate the above-mentioned drawbacks and proposes a composition for diffusing in the air of an enclosure to be treated in order to combat bacteria contained in the air of said enclosure.
According to the invention, this composition comprises 2-phenylphenol and natural and/or synthetic thymol dissolved in a solvent comprising isopropyl alcohol, for example.
Surprising synergy has been found to exist between these two compounds, making it possible to obtain antibacterial action on germs in the air that is considerably greater than the antibacterial action achieved by diffusing either 2-phenylphenol or thymol on its own.
Generally, the composition comprises a proportion by weight lying in the range about 0.05% to 1% of 2-phenylphenol and a proportion by weight lying in the range about 0.05% to 5% of thymol.
Concentrations of 2-phenylphenol and of thymol below the minimum values given above would probably not suffice to achieve the desired ambitious target which is fixed in arbitrary manner as reducing the bacteria contained in the air of an enclosure to be treated by least about 75%, and preferably by at least 80% within 24 hours of an antibacterial composition of the invention being diffused for a relatively short length of time, about 20 minutes.
Concentrations of 2-phenylphenol and of thymol greater than the maximum values given above would naturally enable the looked-for antibacterial effect to be obtained, and it is therefore entirely possible to envisage diffusing antibacterial compositions of the invention having concentrations by weight of these two compounds that are greater or even much greater.
Nevertheless, these maximum values have been determined to take account of various parameters, in particular cost parameters, so as to ensure that the cost in active components is not excessive commercially speaking, and also for other reasons of a more practical nature.
When antibacterial compositions of the invention are to be diffused by catalytic combustion, it is essential to avoid premature aging of the catalytic burner used.
Whenever possible, antibacterial compositions of the invention must be diffused in such a manner as to avoid generating smoke or compounds that are known to be toxic for the user; as a subsidiary point, the odor generated must be pleasing to the user.
Other criteria can also be taken into consideration when limiting the concentration by weight of one and/or the other of the antibacterial compounds used in the context of the present invention, such as the solubility or the appearance of the composition.
In an advantageous version, the composition comprises a proportion by weight lying in the range about 0.1% to 0.3% of 2-phenylphenol and a proportion by weight lying in the range about 0.2% to 2% of thymol.
In a preferred version, the composition comprises a proportion by weight equal to about 0.2% of 2-phenylphenol and a proportion by weight lying in the range about 0.5% to 1% of thymol.
In both cases, the quantities of 2-phenylphenol and of thymol are well below those of the antibacterial substances commonly employed with known diffusion methods.
The method of the invention gives rise to far fewer secondary effects for the user, and presents toxicity that is much less than that of known methods.
In a preferred embodiment of the invention, the composition comprises a total proportion by weight of 2-phenylphenol plus thymol lying in the range about 0.1% to 5%, and preferably in the range about 0.2% to 1.2%.
The total quantity of active substances employed in the context of the present invention is well below the prior art, and can achieve genuine effectiveness at concentrations by weight that are of the order of one-tenth those of the prior art.
The present invention also provides a method of combating bacteria contained in the air of an enclosure to be treated. This method comprises a step of diffusing an antibacterial composition in the air of the enclosure.
According to the invention, the composition comprising 2-phenylphenol and thymol dissolved in a solvent is diffused in such a manner that said solvent is to be found entirely in the gaseous state.
Advantageously, said composition is diffused by means of a catalytic combustion burner, the solvent being combustible and comprising, for example, isopropyl alcohol.
In the implementation of the method of the invention of combating bacteria, the invention also provides the use of a catalytic combustion flask adapted to contain a combustible composition and to receive a catalytic combustion burner on a collar fixed to its neck, said burner having a substantially axial cavity that is downwardly open and that receives a mesh dipping in said composition, the burner optionally presenting a substantially axial annular groove extending from the top surface of the burner and separating an annular peripheral zone supporting the catalyst from a catalyst-free central zone forming a vaporization zone, and/or a channel for putting the top portion of the cavity receiving the wick into communication with the atmosphere.